Oh, but I'm actually wanting to schedule an exam after 8/15. Besides, they took my $100 ages ago -- this is actually just a reschedule. Anyone else testing after 8/15? Perhaps it's just a temporary online scheduling glitch.

Try giving PSI a call. I was able to schedule my exam for September last month and I even rescheduled the timing recently without an issue. PSI will send you an email confirming your rescheduled exam time/date.